Sash-balance.



No. 744,996. PATENTED Nov. 24, 190s. W. BERRY. sAsH BALANCE.

APPLICATION FILED JAN. 9. 1903.

N0` MODEL.

` PATENT Patented November 24, 1903.

EEicE.

WASHINGTON BERRY, OF CHICAGO, ILLINOIS.

SASH-BALANCE.

SBECIFICATION forming part of Letters Patent No. 744,996, dated November 24, 1903;.

Application filed January 9, 1903. Serial No. 138,381. (No model.)

To all whom it may concern:

Be it known that I, WASHINGTON BERRY, a citizen of the United States, residing at Chicago, Cook county, Illinois, have invented certain new and useful Improvements in Sash Balances, of which the following is a specification.

This invention relates to improvements in sash-balances of the class in which a torsional spring is employed to balance the weight of the sash instead of the customary cords, pulleys, and weights.

The general features of my invention comprise window-sasheshavingarack-and-pinion movement in their guides, a spring in the window-ca`sing connected at one end to the rackand-pinion movement for the upper sash and at the other end to the rack-and-pinion movement for the lower sash, such spring being put under strain by the descent of either or both sashes and exerting the force so acquired when either sash is lifted.

The construction of the apparatus for carrying out the above-mentioned objects and included in the general features alluded to is `fully hereinafter described and is shown in drawings accompanying this specification, in which- Figure 1 is an elevation of that portion of a window frame or casing adjacent to the shashes, showing the runways for the upper and lower sashes. Fig. 2 is an elevation of a portion of both sashes and the casing, the latter being partly broken away to show the connection of the spring with the lower sash.

A represents the casing of a window, B the upper sash of the same, and C the lower sash, all constructed in the usual or any desired manner. In the edge of each sash, adjacent to the sash-run, is secured a vertical rack-bar D, extending, preferably, the entire length of the sash. Journaled in the window-casing and projecting through the bottom of the sashrun are two spur-pinions E F, the former engaging with the rack upon the upper sash and the latter with the rack upon the lower sash, the pinions thus being placed out of line a distance apart equal to the space between the two racks or approximately to the distance from the middle of the edge of one sash to that of the other. These two pinions are connected and acted upon by a spiral spring G, containedwithin the window-casing and extending a sufficient distance above and below the meeting-rails of the two sashes. The spring may be a plain spiral, as shown in the drawings; but I prefer to use the double returning-spring described in my United States Patent No. 470,655, March 15, 1892. The con nection between the spring and the spur-pinions is effected by intermediate bevel gearwheels I-I H' I I. The gear-wheel H is keyed upon a rotary shaft h, to which one end of the spring is attached, while the gear-wheel I-I is similarly secured to the shaft or pin h', which carries the spur-pinion E. In like manner the bevel-pinions I and I are respectively secured to pins t' and c, the latter of which carries the spur-pinion F for the lower sash.

In placing the sashes in position the upper sash is first engaged with the rack as near the top of the window as possible and is allowed to fall, putting the spring under partial tension by partly Winding it up from one end. The lower sash is then inserted, so that the pinion F will engage with the rack near the bottom of Vthe sash. The winding of the spring is then completed from the lower end by lowering the sash. The tendencyof the spring is now to throw both sashes up, and this tendency is increased by the gravity of both sashes, which acts to wind up the spring at both ends. The amount of winding or torsional strain to be given the spring is of course proportioned to the size of the spring and to the weight 0f the two sashes.

As before explain-ed, it is preferable in heavy windows to use the spring balancing device upon both sides of the window, but in case of light sashes one will be found suliicient. Ordinarily'in the latter case a plain rack and pinion or antifriction-rollers would be applied to the opposite side of the sash and frame to preventthe sashes from binding in the runways.

I have shown in the drawings a sash-lock for each of the two pinions E and F which is substantially similar in construction to the device described in my Patent N o. 456,716, July 2S, 1891. This consists of a locking-bolt K, sliding in a box L in the window-casing, so as to engage with the pinion. The bolt is provided with lugs Z, which are acted upon by the two-armed cam M through the projecting- IOO rod and handle N, the turning of which in either direction will release the bolt from engagement with the pinion. The construction of the lock is the same for both sashes, eX- cepting that the rod N must be lengthened in the upper part of the window to reach the pinion for the upper sash.

mechanisms comprising a torsion-spring extending vertically and arranged to be affected when either sash is operated.

2. In a sash-balancing device, the combination with the window-casing having sashruns for the upper and lower windoW-sashes, a torsionspring in said casing extending above and below the meeting-rails of the two sashes, a rack upon each sash adjacent to its sash-run, a spur-pinion in the window-casing engaging with each of said racks, the said torsion-spring in the casing having its ends connected to said pinions through intermediate gearing whereby the spring willbewound or put under torsional strain by the descent of either sash, substantially as set forth.

In testimony whereof l affix my signature in presence of two witnesses.

WASHINGTON BERRY.

lVitnesses:

F. H. DRURY, E. SHAsBnRGER. 

